I think that much of what you're hearing is a gross misinterpretation of this article by Rachel Cosgrove, the respected trainer/author. As is so often the case in the fitness industry, fads dominate the landscape and the current fad of Cross-fit a... read more
It is a good exercise from a cardio standpoint, but the reason gym trainer's advise more is because of it's cons. Running for long amounts can cause knee and hip problems. In addition, you spend 1 hour running and you will most likely burn anywhere from 300-800 calories (if you can run for an hour straight), but a 45 minute circuit in the weight room will burn 400 calories. read more